Method of manufacturing metals.



UNITE STATES PATENT FFICE.

HANS GOLDSGHMIDT AND OTTO WEIL, OF ESSEN-ON-THE-RUHR, GERMANY, ASSIGNORS TO THE FIRM OF TH. GOLDSOHMIDT, OF ESSEN-ON-THE-RUHR, GERMANY;

METHOD I OF MANUFACTURING METALS.

Specification of Letters Patent.

Patented. Aug. 1 1, 1908.

Application filed October 9, 1905. Serial No. 282,050.

process and for producing such metals westart with the metallic oxids such as oxid of chromium for the purpose of producing chromium. The metal thus produced has found a wide range of use in the steel manufacture and large quantities of same are wanted there, for the advantages of using such metals free from carbon have been tested and generally acknowledged. As the price of the metal is high it is naturally a desideratum to cheapen the process of production.

Now it is the object of our invention to make the above mentioned Goldschmidtprocess a more economical one or in other words to increase the output of metal over the one roduced in the Goldschmidt-process but wit out increasing the quantities of chromium oxid used.

In the Goldschmidt rocess an oxid of chromium Cr O is emp oyed, which represents the lowest degree of oxidation ap licable for ractical purposes. Now it as been foun that by using Cr O a comparatively small out ut of metal is gained, which result is due to t e slow proceeding of the reaction taking place, so that but little metal separates. If however, chromium of a higher degree of oxidation is used, the reaction sets in too quickly, its course is a rather turbulent one and involves danger as well as loss of metal The employment of our method as described herein avoids these defects and increases the output ofv metal by about 30-40%.

The most important novelty of our new method is the fact discovered by us, that but a comparatively small quantity of metallic oxid of a higher degree of oxidation will suffice as addition to the well known Goldschmidt mixture to bring about the desired result, for example 1% of chromic acid added to oxid of chromium. This additional small' percentage of oxidof high degree of oxidation serves as a stimulant for a faster reaction to take place and atthe same time it causes the formation of an easily melting slag, whereas the usual chrome slag is known to have a high melting power. r

In carrying out our process in practlce it is of considerable advantage, if the slag is prevented from becoming rigid too soon, as thls result assists a good deal in gaining a fine regulus of chromium.

Thus the feature of our invention consists in the mixture of a small quantity of a metallie oxid of a high degree of oxidation with 'a large quantity of metallic oxid of a low degree of oxidation, of which mixture the oxid of higher degree serves the purpose of qulckening the ace of the reaction and the o x1d of lower egree acts as a safeguard agalnst dangerous eflects and destruction of metal during this reaction.

We shall now attempt to show by way of example, how the process of manufacturing. chromium is carried out according to our method; 100 kilos of pure oxid of chromium are thoroughly mixed with 34 kilos of chromic acid, to which mixture 3435 kilos of aluminium of finest granulation are added. The reaction is then started in this mixture by igniting at a point in the manner well understood in the above mentioned Goldschimdt process. In this composition the articles of chromic acid evenly distributed 1n the whole mixture, serve as an agent for initiating .and transmitting the reaction to all parts of the mass.

We claim;-

1. Method of manufacturing metals according to the alumino-thermic process consisting in mixing an oxid of the metal concerned with anotheroxid of the same metal of higher oxidation and adding thereto finely granulated aluminium, then igniting the mixture in order to start the reaction.

2. Method of manufacturing metals according to the alumino-thermic process consisting in mixing an oxid of the metal concerned of low oxidation with a very small 3. Method of manufacturing chromium chromic acid with chromium oxid (Cr,,O

' adding thereto finely granulated aluminium In witness whereof we have hereunto set and then starting the reaction by igniting. our hands in the presence of two witnesses. 10

4. Meth( )d of manufacturing Chrqmium conslsting 1n mlxlng 3 parts of CllIOIIllC acld OTTO WEIL with 100 parts of oxid of chromium (Cr o adding thereto 34 parts of finely granulated Witnesses:

aluminium and then starting the reaction by WILLIAM EssENwEIN,

igniting the mixture. RUDz LIEBER. 

